Indicating device



Nov. 24, 1953 E. BoHNr-:T

INDICATING DEVICE Filed July 17, 1950 A INVENTRZ Lwe Gm.- BY

Patented Nov. 24, 1953? UNITED STATES ATF-,NT OFFICE amateure@ Busan This invention relates to .indicating devices andmore' particularly to an'` indicatorA for vdeterminingl the eccentricity of a cylindrical surface. off" a workpiece mountedv ai lathe, boring. or millingl machine yor the-like so'l thaty adjustment. of the chuck'ca-n be made to bring the axisaof such cylindrical` surface into coincidence withv the axis of the rotatable chuck;

`The l primaryA object of the .present invention. isf/to provide such anv eccentricity indicator .for4 centering the*` workpiece or either an` internal orV` external? surface' vthereon .with .respectzto .thea axis` of' rotation ofthe chuck-holding thelworkpiece.:

Another object is tov provide' suchz an. eccen` tricityV indicatorA which indicates `the .degree .of

eccentreityy and'y ltherefore indicates the'y degree; ofadjustment of the vchuck in order .to render the workpiece concentric.y

Another object is to provide such an/.eecentricity indicator which canbe supported. atany desired angle within a wide range with.` respectto the workpiece and' alsowith respect tofthe. part of the machine holdingthef-indicator'.such

asaitool post cna lathe;

A1 further object is-.toprovide sucha-an ,eccerv tricity vindicator which is 'simple'. in construction",`

reliable andi eiiicient' in: operation. easily readv and very sensitive in action and also'-mayf be:

manufactured atflow'cost.

Other. objects and .advantages of thevinventionwillebeiapparent fromthe following. descrip.- tion and accompanying:drawingsin which:

Fig; 1 is-a .fragmentary plan view of a lathe showing .an eccentricity indicator embodyingthe present invention mounted thereon.

lig. 2 isatop plan View on a greatlyenlarged. scale of the eccentricity indicator showen'v inA Fig; 3` is atvertical transverse sectionalyievv-I thereof taken on line 3-3,` Fig. 2.rv

Fig. ,4. is .a vertical longitudinal sectional view thereof taken .on line .4f-ll, 2.

Fig, 5 is., a. fragmentary horizontalsectional` -Referring; to Fig; 1, the leccentricity indicator.:

embodying f the; present'v invention is: shown@ `for illustrativev purposes. only,4 as f mountediin ,the conventional .tbolv post IU of. aplathe: indicated# The .lathe H 1isi shown aswhav` generallyat Il. ngla chuck-i12iholdingza'fworkpiece. I3. vThe ece centricity.indicator is .set'up for: determining.the eccentricity i of: anxinternal :cylindrical surfacepon. the.workpiecer.|3 sov that1therchuck l2 can be'.V adjusted; to;l hold this. surface.. with. its axisnconf centric .withithatf o1" the .headstockf spindle :14.1

surroundingthesame.

Af bolt member 22?'is'shown las having its shank jo'urnaled in the flower 4.narrovv part of the bore i8 for rotation relative tof the lieadl Hl The upperr end' o'fthe bolt member: 2211 i'sf shown as formed: to providel an enlarged cylindrical integra-lehead 23 having its1lower surface seating onthe surface'Z-'l'` anditszupper surface on about thef same level asti-ie upper surface of the head |62 The'diame'ter rof` the head. 23 vis `greater than the Width ofi the head l-lV iso' that.' portions of:v the head- 23 extends-:1 outwardlyl 1through the side openings-20:v /Theinperiphery of the headJZS isV preferably knurled as shown so as to'fpermit. it to `be graspedi for turning the same relativeto therstationary'head I6.

The; bolt; member 22 is* arranged for angularl adjustmentrelative tothe'head I6 about arverticalzaxi'sA and means .are provided* for permitting andvmaintaining tl'ierclesire'd;` adjustmenti Such means: are shown:l as." comprising a` nut .member 24, Washer 251 andrspringf. TheV Washer 25 surroundsv the :shank ofi. the bolt member A22 .and

bears saganstrthe bottomflat surface of thehead- I6. The nutlmemberz24 workson .the externally,

threaded'.lower` end of theushank of' the bolt member- 22. Thefspringl is vofhelical form and` surroundsthe-fshank of the bolt member 22- and its.` upper. end-bearsagainst the bottom of the Washer `25 and; itsl lower. end bears:` against` the nut member 24. This nut member` 24 is. also shownxasformed With an upstanding Ycylindrical tubular `neck which:` surrounds ,the spring 26I and the upper: end vof .thissneckuisadapted to engage theabottomzof the :Washer 25;

It Will thus be seenthatWiththeinutmember Matightened". down aagainst .the Washer 25, .the

head 23 of.thefboltmember:22..isfclamped against.

thesurfaceiZlof the head-.wand this ,bolt `memberis prevented 1 from turning' relative toV` the i head@ 6: Howeven. loosening vthe .nutf' member' 211i permits .the-bolt memberl 225A to.` be turned tc any 1:angularf.positionfrelative fto.. thefhead .i 6; the; .SPrIlgJf-lserving tol@holdithemlower surface 2st;

part of the bore--l8`-afnd= of the head 23 in engagement with the surface 2| of the head I6 while the nut member 24 is so loosened. The periphery of the nut member 24 is preferably knurled as shown to permit of its readily being turned.

'I'he head 23 of the bolt member 22 is arranged to movably hold a rod or needle 29 one end of which is adapted to engage the workpiece I3 and the other end of which is adapted to traverse a scale 21 thereby to indicate the degree of eccentricity. As shown, the rod or needle 29 eX- tends through a horizontal hole in a ball-shaped holder 30 and is held in place by a set screw 3|. This holder 39 is partially arranged in an upwardly opening recess 32 in the enlarged head 23 of the bolt member 22 and is pivotally mounted on the side wall of this head. As best shown in Fig. a pair of trunnion pins 33, 33 extend coaxially laterally from the holder 30 at right angles to the longitudinal axis of the rod or needle 29. These trunnion pins 33 are journaled in semi-circular bearing recesses 34, 34 formed in the rim of the head 23. Each of the top halves of these trunnion pins 33 is held in place by an arcuate bearing cap 35 which is seated on the rim of the head 23 and centered thereon by dowel pins 36 and held in place by screws 38.

The scale 21 Yis connected to the outer end of a horizontal arm 39 which is mounted on one of the bearing caps 35 and secured thereto by a screw 49.

The rod or needle 29 is normally held in a horizontal position or in a position extending at right angles to the axis of the bolt member 22. For this purpose, the side wall of the head 23 of the bolt member 22 is slotted on opposite sides thereof underneath the rod or needle 29 as indicated at 4l. Both these vertical slots 4| are of the same depth and in each is arranged a helical compression-spring 42 having its lower end seating on the bottom of the respective slot and its upper end bearing against the rod or needle 29. The slots 4I are preferable substantially circular in cross section so as to coni-lne the springs 42 therewithin.

The springs 42 are identical in size and shape so as to exert the same force against the rod or needle 29 when the latter is in a horizontal position as shown in Fig. 3, these springs being under a slight amount of compression when in this position. Since these springs engage the rod or needle 29 at the Same distance from the axis of rotation of the trunnion pins 33, equal but oppositely directed torques are applied and the rod or needle is maintained in a centered horizontal position. As well as this centered position being indicated by one end of the rod or needle 29 being opposite a particular graduation on the scale 21, a scale d3 can be provided on the upper surface of the holder 30 and adapted to traverse a reference line 44 on the adjacent upper surface of the adjacent bearing cap 35.

It will be seen that the rod or needle 29 can be placed at any desired angle relative to the head I6 within the range determined by the horizontal distance between the vertical side edges of one of the openings 29.

Also different shapes of rods or needles 29 can be used. If an internal cylindrical surface is to be checked for eccentricity as shown, the end of the rod or needle 29 which is adapted to engage the workpiece is turned or bent as indicated at 45. The end 45 is then placed inside the workpiece and brought in contact with the internal surface to be tested. If this surface is eccentric with respect to the axis of the head stock spindle the rod or needle 29 will oscillate up and down, thereby indicating through the graduations on the scale 21 the degree of eccentricity.

If a straight rod or needle is used the end of it may be placed in the center punch mark of the workpiece. If this punch mark is out of center the rod or needle wabbles to show such eccentricity.

If the eccentricity of the outside diameter of a workpiece is to be checked, the end of the rod or needle is placed against the external surface of the workpiece while revolving the latter and eccentricity of such surface will likewise be indicated by fluctuations of the rod or needle.

From the foregoing it will'be seen that the present invention provides a versatile, simple, sturdy, easily usable and sensitive eccentricity indicator.

I claim:

1. An eccentricity indicator, comprising abody having a bar for holding the indicator and a head at one end of said bar, said head being provided with a bore extending therethrough and one end of said bore being enlarged to a diameter greater than the width of said head so as to provide side openings on opposite sides of said head, a bolt member journaled in said bore and having an enlarged head at one end arranged within said enlarged portion of said bore and projecting through said openings, means arranged to maintain the angular adjustment of said bolt member relative to said head, said head of said bolt member being provided with a recess opening to one axially facing side thereof to provide an annular wall, a holder arranged in said recess and journaled on said annular wall for pivotal action about an axis extending at right angles to the axis of said bore, a rod mounted on said holder and extending laterally therefrom, the outer end of said rod being adapted to engage a surface the eccentricity of which is to be checked, and a spring arranged in an axially extending slot in said annular wall on opposite sides of the pivotal axis of said holder and bearing against said rod to urge said rod to a normal centered position, said rod being adapted to enter said slots.

2. An eccentricity indicator, comprising a body having a bar for holding the indicator and a head at one end of said bar, said head being provided with a bore extending therethrough and one end of said bore being enlarged to a diameter greater than the width of said head so as to provide side openings on opposite sides of said head, a bolt member journaled in said bore and having an enlarged head at one end arranged within said enlarged portion of said bore and projecting through said openings, means arranged to maintain the angular adjustment of said bolt member relative to said head, a holder, trunnion pins extending eoaxially laterally from opposite sides of said holder, said head of said bolt member having semi-circular bearing recesses receiving said trunnion pins, the axis of said bearing recesses extending at right angles to the axis of said bore, a pair of bearing caps arranged on said head of said bolt member one over each of said trunnion pins and each having a semi-circular bearing recess receiving the corresponding one of said trunnion pins, a rod mounted on said holder and extending laterally therefrom at right angles to the axis of said trunnion pins, the outer end-of said rod being adapted to engage a surface the eccentricity of which is to be checked, and yielding means on opposite sides of said axis of said trunnion pins and operatively interposed between said rod and said head of said bolt member and arranged to urge said rod to a normal centered position.

3. An eccentricity indicator, comprising a body having a bar for holding the indicator and a head at one end of said bar, said head being provided with a bore extending therethrough and one end of said bore being enlarged to a diameter greater than the width of said head so as to provide side openings on opposite sides of said head, a seat on said head and surrounding said bore and facing said enlarged portion of said bore, a bolt member journaled in said bore and having an enlarged head at one end arranged Within said enlarged portion oi said bore and projecting through said openings, and also having a part engaging said seat, means arranged to clamp said part of said bolt member against said seat for maintaining the angular adjustment of said bolt member relative to said head and including a nut member having an adjustable threaded engagement with said bolt member and arranged for thrust engagement with said head of said body, a washer surrounding said bolt member and arranged between said head of said body and said nut member and a spring arranged between said washer and said nut member, a holder, trunnion pins extending coaxially laterally from opposite sides of said holder, said head of said bolt member having semi-circular bearing recesses receiving said trunnion pins, the axis of said bearing recesses extending at right angles to the axis of said bore, a pair of bearing caps arranged on said head of said bolt member one over each of said trunnion pins and each having a semi-circular bearing recess receiving the corresponding one of said trunnion pins, a rod mounted on said holder and extending laterally therefrom at right angles to the axis of said trunnion pins, the outer end of said rod being adapted to engage a surface the eccentricity of which is to be checked, and a spring on opposite sides of said axis of said trunnion pins and operatively interposed between said rod and said head of said bolt member and arranged to urge said rod to a normal centered position.

4. An eccentricity indicator, comprising a support bar, a bolt member rotatably mounted on said bar at one end thereof, means arranged to maintain the angular adjustment of said bolt member relative to said bar, said bolt member having an enlarged head which is provided with a recess opening to one axially facing side thereof to provide an annular wall, a holder arranged in said recess and journaled on said annular wall for pivotal action about an axis extending at right angles to the axis about which said bolt member is rotatable, a rod mounted on said holder and extending laterally therefrom, the outer end of said rod being adapted to engage a surface the eccentricity of which is to be checked, and a Spring arranged in an axially extending slot in said annular wall on opposite sides of the pivotal axis of said holder and bearing against said rod to urge said rod to a normal centered position, said rod being adapted to enter said slots.

EMIL BOI-INET.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date 617,501 Fay Jan. 10, 1899 773,425 Riggs et al Oct. 25, 1904 1,648,428 Stacy Nov. S, 1927 1,660,986 Berlowitz Feb. 28, 1928 1,936,160 George Nov. 21, 1933 2,150,577 Bernhardt Mar. 1li, 1939 

